JP2002198621A - Flexible printed circuit and fixing method thereof - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a flexible printed circuit with high connection reliability at low cost with a simple structural change. SOLUTION: A flexible printed circuit 1 is made of PET.
And a wiring pattern 12 made of copper foil formed on the base film 11. The wiring pattern 12 has a ground wire 14 in a part thereof, and the ground wire 14 is grounded to a mounting portion of the vehicle body to form a ground circuit. Part of the ground wire 14 is the base film 1.
1 and projecting from the edge of the mounting hole 13.
Are formed. Hole 13 is surrounded by a ground wire 14
The pad 15 is surrounded by a pad 15 made of a conductive material formed thereon, and the pad 15 electrically covers the ground wire 14 thereunder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible printed circuit such as an FPC (flexible printed circuit) harness having a mounting hole formed therein and a method of fixing the same.

[0002]

2. Description of the Related Art Flexible printed circuits are usually PE
It is formed by forming a circuit pattern such as a copper foil on a film sheet such as T. When a ground wire is included in this circuit, a conductive member (for example, L
A terminal, etc.), and this is fixed to the vehicle body with bolts or the like to form an earth circuit. FIG. 5 shows a main part of a ground circuit of a conventional flexible printed circuit 7. As shown in FIG.
The LA terminal 6 having the hole 61 is attached to the flexible printed circuit 7 by a technique such as soldering or welding.
On the side of the flexible printed circuit, solder plating 75 is provided on a copper foil 72 constituting a ground wire 74 as a pad for attaching a terminal. In this example, LA
The terminal 6 is connected to the flexible printed circuit 7 by welding 76.
Attached to. FIG. 6 shows a conventional flexible printed circuit 7 fixed to a fixing hole 8 of a mounting portion 8 of a vehicle body by a bolt 9.
FIG. 2 is a perspective view showing a state of being attached to the first.

[0003]

In the above-mentioned method, connecting the LA terminal to the flexible printed circuit is costly and increases the number of parts. Further, since the number of connection points is large, the connection reliability from the flexible printed circuit to the vehicle body is low.

The present invention has been made in view of the above problems, and has as its object to provide a low-cost, high-reliability flexible printed circuit with a simple structural change.

[0005]

According to the present invention, there is provided a flexible printed circuit comprising a base film, a wiring pattern formed on the base film, and a mounting hole formed in the flexible printed circuit. The wiring pattern includes a ground wire, and the hole is formed on or near the ground wire,
A pad surrounding the hole and electrically conductively covering at least a part of the ground wire with at least a part thereof is further provided.

Another flexible printed circuit according to the present invention includes a base film, a wiring pattern formed on the base film, and a coverlay covering the wiring pattern, and has a mounting hole. In the flexible printed circuit in which is formed, the wiring pattern includes a ground line, the hole is formed on the wiring pattern of the ground line, and around the hole, the coverlay is formed. The wiring pattern is exposed by being removed.

According to a method of fixing a flexible printed circuit according to the present invention, the hole of any one of the above-mentioned flexible printed circuits is matched with a hole on the vehicle body ground side, and the hole of the flexible printed circuit is connected to the hole on the vehicle body ground side. A metal member is screwed into the portion to conduct the ground wire and the vehicle body ground.

According to the present invention, a mounting hole is formed on or near the ground line of the wiring pattern on the base film, and a conductive pad is formed around the hole, or a coverlay around the hole is formed. And the ground connection by fixing itself using this hole eliminates the need for an additional LA terminal, thereby reducing costs, improving assembly, and improving the reliability of the ground connection. And a method for fixing the same.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments according to the present invention will be described below with reference to the accompanying drawings. FIG.
FIG. 2 is a plan view illustrating a main part of the flexible printed circuit 1 according to the embodiment of the present invention. The flexible printed circuit 1 according to the present invention comprises a base film 1 made of PET.
1 and a wiring pattern 12 made of a copper foil formed on the base film 11. The wiring pattern 12 has a ground wire 14 in a part thereof, and the ground wire 14 is grounded to a mounting portion of the vehicle body to form a ground circuit. The protruding part 1 whose part protrudes from the edge of the base film 11
6, and a mounting hole 13 is formed in the inside thereof so as to penetrate the ground wire 14. Hole 13 is
The periphery thereof is surrounded by a pad 15 made of a conductive material formed on the ground wire 14, and the pad 15 covers the ground wire 14 thereunder in a conductive state. FIG. 2 is a sectional view showing the vicinity of the hole 13 of the flexible printed circuit according to the present embodiment. As shown in FIG. 1, a wiring pattern 1 made of copper foil having a predetermined wiring pattern is formed on a base film 11.
2 are formed. The hole 13 is surrounded by a pad 15 formed by solder plating, and the pad 15 and the wiring pattern 12 are electrically connected. Other areas are protected by the coverlay film 19.

FIG. 3 is a perspective view showing how the flexible printed circuit is mounted on a vehicle body. As shown in the drawing, the mounting holes 13 formed in the flexible printed circuit 1 and the holes 81 provided in the mounting portion 8 of the vehicle body are aligned with each other, and bolts made of a conductive material such as metal are used. 9 is used for mounting and fixing. Thus, the ground circuit can be formed by attaching and fixing the entire flexible printed circuit to the attachment portion 8 of the vehicle body via the pad 15 with the bolt 9 made of a conductive material.

In the above example, the pad 15 is formed by solder plating. In addition, as shown in FIG.
By providing a region 15 ′ without a coverlay, conduction may be obtained instead of the pad 15.

In this embodiment, the projection 16 is provided at the edge of the base film 11 and the mounting hole 13 is formed in the projection 16.
Mounting hole 1 as long as it does not come into contact with other wiring patterns
By arranging 3 inside the base film, the size of the protrusion 16 can be reduced. As a result, the area in which material is wasted due to the protruding portion 16 can be minimized, and the yield can be improved.

[0013]

As described above, according to the present invention, the mounting hole is formed on or near the ground line of the wiring pattern on the base film, and the hole is fixed by using the hole to secure the ground. Since the connection is made, it is not necessary to add an LA terminal, so that it is possible to provide a flexible printed circuit that can reduce costs, improve the assemblability, and improve the reliability of the ground connection.

[Brief description of the drawings]

FIG. 1 is a plan view showing a main part of a flexible printed circuit according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a main part of the flexible printed circuit according to the embodiment of the present invention.

FIG. 3 is a diagram for explaining a method of attaching a flexible printed circuit to a vehicle body according to an embodiment of the present invention.

FIG. 4 is a sectional view showing a main part of a flexible printed circuit according to another embodiment of the present invention.

FIG. 5 is a plan view showing a main part of a flexible printed circuit according to a conventional embodiment.

FIG. 6 is a view for explaining a method of attaching a flexible printed circuit to a vehicle body according to a conventional embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Flexible printed circuit, 11 ... Base film, 12 ... Wiring pattern, 13 ... Hole, 14 ... Ground wire, 15 ... Pad, 19 ... Cover lay, 8 ... Mounting part, 81 ... Mounting hole, 9 ... Bolt.

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Yasuo Takemura 1440, Murosaki, Sakura-shi, Chiba F-term in Fujikura Sakura Office (reference) 5E338 AA12 AA16 BB02 BB13 BB25 CC01 CC06 CD33 CD40 EE11 5E348 AA25 AA32 EF36

Claims (3)

[Claims] 1. A flexible printed circuit comprising a base film and a wiring pattern formed on the base film, wherein a mounting hole is formed, wherein the wiring pattern includes a ground wire, The hole is formed on or near the ground wire, and further includes a pad made of a conductive material that surrounds the hole and covers at least a part of the ground wire in a conductive manner at least in part. A flexible printed circuit characterized by: 2. A flexible printed circuit comprising a base film, a wiring pattern formed on the base film, and a cover lay covering the wiring pattern, wherein the flexible printed circuit has a mounting hole formed therein. The pattern includes a ground line, wherein the hole is formed on a wiring pattern of the ground line, and around the hole, the cover lay is removed and the wiring pattern is exposed. A flexible printed circuit characterized by the above. 3. The flexible printed circuit according to claim 1 or 2, wherein the hole is aligned with a hole on the vehicle body ground side.
A method of fixing a flexible printed circuit, wherein a metal member is screwed into a hole of the flexible printed circuit and a hole on the vehicle body ground side to conduct the ground wire and the vehicle body ground.